MAPK8 and ovarian cancer: We previously provided evidence that, in ovarian cancer cells, 4-HPR induced apoptosis through a signaling cascade starting from ROS production and involving endoplasmic reticulum (ER) stress response, Jun N-terminal Kinase (JNK) activation, and induction of the proapoptotic PLAcental Bone morphogenetic protein (PLAB, also known as NAG-1, GDF15, MIC-1, PDF, and PTGFB) (ROS → ER stress → JNK → PLAB) [11], [12].